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Topic: Dual Fuel Gingery Type Furnace (Read 23818 times)

inthesticks

Managed to get a full afternoon in the shop today sunny and cool great working weather. Today I built the arch braces and mounted the lift winch. In the first 2 pictures are the finished braces and the braces bolted to the arch and deck with (8) 3/8 X 3/4" NC bolts. The next picture is the winch plate bolted to the braces with (4) 3/8 X 3/4" NC bolts. Below is the worm winch I will install. It is rated for 2000 lbs. certainly overkill but I had 2 on the shelf just waiting for a project.I also had 2 smaller boat type winches but these are not recommended for this application. The worm winch will lock in any position when you release the handle without fiddling with pawls. in the last 2 pictures are 2 views of the winch mounted with (3) 1/2 X 1" NC bolts.

inthesticks

Didn't get alot done today, the old body isn't what it was anymore. Fitted 25' of cable to the winch. Cut and welded up lift guide. Checked guide fit to arch and total lift. 2nd picture at bottom, 3rd picture at top of lift, total travel 22"

inthesticks

Puttered around in the shop last couple days, fitted lift arms and lid lift guide to body lift guide. reassembled the works and made some adjustments to get the right fit. For thoughs not familiar with this type of lift it is really 2 lifts working with each other. The main body lift will lift both the body and lid and will only be used when you are ready to pour. The lid lift will be activated with a foot pedal allowing you to swing the lid away from you and the top of the furnace allowing you to check temperature or add metal to the melt. The lid lift rod is guided by a tube welded to the main body lift.

Hope these pictures help and will become clearer with the building of the lid lift next.

inthesticks

Hello Dave Yes with me the muscles are willing but the joints complain all the time. Patio stones are always a good workout. Glad to hear your going to build a furnace ,I always look forward to seeing the new ideas people come up with.

Did some work this morning. I have been trying to figure out a way of locking the lid lift in the raised and lowered position, not really neccessary with a steady foot on the pedal but for conveneance and safety it was sticking in the back of my mind. A dig through my magic junk box came up with a spring loaded plunger and a flat bar from a broken quik clamp. The pictures show what I came up with .

inthesticks

Managed to complete the lid lift this afternoon. The first 2 pictures show the struts, lift rod and method of attachment.1 more day finishing off the cosmetics and this stage is basically done. Next refractories and burners.

inthesticks

Thank you Rob. I still have to make a trip down south for refractory supplies. In the mean time I am trying to modify a surplus fan I have to get the outlet pressure I am looking for. If unsuccessful I have a spare 3/4 HP dust collector fan that will do the trick. As this is a cost to the bottom line of operating the furnace I would rather not go oversized here.

CheersCB

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inthesticks

Well looks like I made some progress on that fan. The 2 old salvaged fans I had in storage have squirrel cage wheels, good for volume not for pressure and the motor only draws 1.5 amps at 120V. I have a couple nice motors drawing 3.5 amps-1/4 HP which would be preffered. Using D. Gingery's book "How To Design And Build Centrifugal Fans" as a guide I made and installed 4 radial type blades into the original fan runner. These should increase pressure without impacting volume. I also made a adapting plate for the new motor. After reassembly I started it up and found the outlet pressure is 3-4 times previous. This was determined by simple hand over outlet press. I will eventually confirm this with a manometer I am looking for at least 3"s water column. The old fan was no more than 1".This fan will ruffle my T-shirt standing 16' away. I will use this on a propane burner and and if it puts out enough to burn oil all the better.I was concerned about vibration from imbalance But it ended up running quietly and vibration free a little luck and the small diameter of the runner no dought.Pictures 5 and 6 is the damper I installed to control the inlet.

inthesticks

Haven't done to much on the furnace lately, been mostly aquiring materials. Finally made that trip to the Toronto area for refractory material. In the first picture are the materials I now have. I hope this will do for at least 3 projects, the only thing missing is Durablanket 2600 which the supplier did not have in stock, no problem its light enough to ship anytime I plan to use it for a future forge project. The products from left to right, 2 pails of 3000* firebrick morter, 5 bags of castable 3200* hotface, 3 bags of fireclay, on top 2 1/2 boxes of A P Green G-26 insulating firebrick and 5 bags of Bentonite clay for making green sand, 3 bags of southern recommended for aluminum and 2 bags of western recommended for the heavier metals brass and iron.

The second picture are the popane tanks on the pad I cast a few years ago for this purpose. The plan is to pull from the 2 30# tanks. They will be tide in to the 100# tank with a switch over valve in case I run out in the middle of a melt or if I need higher press on a cool day. I went with the 2 smaller tanks for regular use because they will be easeir and more conveniant to transport for refilling. Some would say thats alot of expence for a hobby but that is not their only intended use. By far the majority of power outages around here only last 2 or 3 hours, usually a tree on the line somewhere. I have a small propane generater that I want to use in these cases as opposed to my large gas fired generater which is a bit of a waste if all you need is lights, electronics and a cup of coffee for a couple hrs. I'll revisit this when my connections and piping are all done.

Almost forgot I also picked up a clay graghite #8A crucible to try out an iron melt or two I hope.

inthesticks

Hello all, soggy wet day out there today but still managed to complete the waste engine oil day tank. The tank when in use will hang from my garage eave from a pulley and lift rope. The hieght will be 10' giving about 4 PSI at the burner (borrowed idea). The tank will be heated by a 300 watt KATS magnetic block heater (my idea) Temp will be checked periodically with a laser pointer temperature gun. The oil discharge pipe extends 3" into the tank to act as a stand pipe and prevent the krud settling out of the oil from leaving the tank. The bottom of the oil level site tube is 1/4" above the top of the stand pipe indicating the need for a refill. The cap on the fill pipe has a channel drilled from underneath to allow the tank to breath and prevent a vacuum. The last picture is the tank complete minus the oil hose and a black paint job. To soggy to hang and paint outside today.

If you add a small (say 1 Litre) tank between your main tank and the outlet to the furnace, you could just heat this.It would heat the oil in it much quicker than if you heat the whole tank. An, of course, as the hot oil is used,cooler oils will replace it and in it's turn be heated.

Just an idea. I this sometimes used by the SVO people who need to heat up cold veggie oil for their car fuel pumps.

Dave.

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inthesticks

A good suggestion same idea as a flash water heater as opposed to heating a large storage tank. I don't plan on burning alot of WMO just my own production from yard equipment and vehicles. I now have a full 55 gallon barrel and I don't want to give up the space for another.That said the day tank will only hold 3-4 usefull gallons of oil this is only one large melt or two small ones. My main concern with heating is to get good flow to the burner and promote better seperation of solids at the supply tank and of course raising the temp. will improve combustion. I could complicate the system by adding an oil filter which would require pressurizing the tank bringing my shop compresser into the picture. A small heater like you suggest after the filter would be ideal and certainlly the way to go if oil was my main fuel.The magnetic block heater is a quik and easy solution for occasional use and at 300 watts I will not be reaching temperatures higher than you would expect in engine block heating.

CheersCB

« Last Edit: July 07, 2016, 11:05:24 AM by inthesticks »

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inthesticks

Didn't do much today, should have been out cutting 5 acres of lawn but still to wet to cut grass, so puttered around in the shop instead. Built a transition piece for the burner fan, built a rough and dirty manometer to check static press. The first picture is the set up. The second picture is the manometer with imput connected but fan off. The third picture is the manometer with fan on and outlet plugged. the reading is the total difference between the two legs, I get roughly 3.1-3.2" water column which is plenty for propane. We will have to see how it handles oil. I can gain a bit sealing the transition piece but not much.

PS: Very humid day today after that rain, reading will also improve some on a less humid day.

inthesticks

This wet weather persists, haven't got outside to hang oil tank but I got it painted up, installed a valve on the outlet so I can disconnect hose for storage. The hose is 24' of one half of an old oxy-acetylene hose I had. I installed quik connectors at both ends for conveniance and so I am not dripping oil all over the place when storing hose.The other item in the picture is the pulley assembly for hanging the tank, maybe tomorrow.

inthesticks

Thanks for your interest LibbyHillBrewer. The manometer I put together is pretty rough, I just wanted to verify I was in the ballpark on this fan. If I build a proper one in the future I will certainly do a write up on it. In the meantime if your interested I made up a PDF which is from D. Gingery's book "How To Design @ Build Centrifugal Fans For The Home Shop". It will show you how to build one and explain the readings.

inthesticks

Well I did manage to finish the dual fuel burner today. The design is virtually the same as Lionel Oliver's "Hot Shot"(1st picture). Mine is one size larger 1 1/4" instead of 1" burner pipe he also used 1/8" black iron pipe for oil injection I used 1/4" brake line tube, and total length is about 3" longer. In a later version he extends the oil pipe to the end of the burner pipe which I did here. I did not have a 2" nipple long enough for the blower pipe and my pipe dies stop at 1 1/2" so I welded 1/2 a close nipple to the end of a 2" pipe. Hey!! it worked . I resisted welding the oil delivery pipe to the blower pipe, threading it instead so that if I need to make changes in the future, it can all be dismantled. Both oil and gas have needle valves for positive control and quik connect fittings.

Many years ago, when I was working in the maintenance dept of our local chicken processing factory, one of our gas fired boilers developed a problem. It would start ok, but when it tried to switch from start to run it just cut out. The electrician couldn't find any electrical problems. I suspected the gas supply. So I made up a crude manometer using about ten foot of 10mm bore clear plastic pipe. I fixed it to a length of plank so that it formed an elongated 'U', added water until the water level was about half way up the pipe (naturally on both sides of the 'U'), and connected one end of the pipe to a spigot on the side of the gas supply pipe.A mark was made on the board coinciding with the level of the water.

And the boiler was switched on.

At first the gas pressure showed, as expected, a positive pressure, not much, about 2" of water if I remember correctly. But when the system tried to go to 'run' the pressure dropped back past the original mark. In other words it was, briefly, pulling a slight vacuum. And there was the problem.

A gas boiler system must never have a negative pressure in it as there is the potential to draw in air. This can lead to an explosive gas/air mix. So the electronics detected the negative pressure and shut the system down.

For very low pressure measurement, manometers are simple, rugged and virtually fool proof. There is nothing to go wrong.

Dave.

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inthesticks

Did you determine why your gas was shuting down. Did you connect to the pilot startup line or your main supply line. Sounds to me like your pilot flame was not lighting off, after a set time on your fireye (or other make) flame senser the startup would be shut down. A properly designed system has more than one check valve in adittion to your control valves and unless you loose press. on your supply side (line break) you would not be sucking air into the system.At startup you supply gas to your pilot. After a predetermined time if the fireye does not detect a flame the system shuts down. The valves sudenlly closing and the momentum of the remaining gas in the pilot supply line could momentarily produce a negative press. But you would not be in danger of sucking air into the lines.

I had nothing else to do with it, but gatherer form later conversations that it was due to the bore of the pipes supplying the gas. It seems they were not really big enough and when the run stage blowers came on the supply briefly dropped below a critical level. A section of bigger bore pipe was fitted leading up to the boiler and the problem went away.

Dave.

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inthesticks

Didn't do a heck of alot of anything today, to hot and sunny not to enjoy it. Did take an hr. out to hang the oil tank. Decided to hang the tank over gravel instead of the high point over the patio in case I spring a leak. Still 9' of head which should be plenty at the burner.